Crown control for rolling mill



CROWN CONTROL FOR ROLLING MILL Filed June 50, 1965 2 Sheets-Sheet 1 1NVE N TOR. JfQ/FMMI/ 14 OZR/E/V ATTORNEV.

Jan. 23, 1968 J. w. O'BRIEN 3,364,715

CROWN CONTROL FOR ROLLING MILL Filed June so 19 5 2 Sheets-Sheet 2INVENTOR. JfQA-M/Af/ 14/. 0272/5 United States Patent 3,364,715 CROWNCONTRGL FGR ROLLING MILL Jeremiah Wagner OBrien, Mount Lebanon, Pa.,assignor to United Engineering and Foundry Company, Pittsburgh, Pa., acorporation of Pennsylvania Filed June 30, 1965, Ser. No. 4 58, 168Claims priority, application Great Britain, July 8, 1964, 28,232/ 64 7Claims. (Cl. 72241) ABSTRACT OF THE DISCLOSURE This invention relates toa rolling mill having a housing in which there is formed a window. Therolls of the mill are provided with bearing-chock assemblies which arereceived in the window of the housing. Outward of the bearing-chockassemblies the rolls are engaged by piston cylinder assemblies designedto apply a bending force on the rolls to control their crowns withreference to their tendency to deflect when subject to the rollingloads. The bending forces are isolated from the housing by providing arigid beam member arranged between the bearing-chock assemblies and thehousing in such a manner that the bending forces are self-contained.

This invention relates to a rolling mill and, more particularly, to thetype of a mill in which there is provided roll deflecting means forcontrolling the crown of the rolls.

In order to obtain close gauge tolerances and flatness, modern millshave been provided with a mechanism for applying roll deflecting forcesto the rolls in order to control their contours. It will be appreciatedthat in a normal rolling mill the rolling loads are applied to thecenter of the roll which flexes or bends the rolls between theirjournals. This flexing, unless taken up by a machine crown which willcompensate for the deflection, produces a product having a variablethickness across its width.

Not only is such a result objectionable from a thickness standpoint, butin certain cases buckles are formed in the strip which cause the stripto be unflatv In an etfort to alleviate these conditions, as previouslymentioned, there have been employed crown control devices which flex therolls to counteract for the inherent deflection caused by the rollingloads. Such devices have been very successfully employed for the backuprolls of 4-high mills, which includes hydraulic cylinders arranged totake two separate forms. The cylinders were either mounted between thejournals of the backup rolls, whereby two cylinders provide equal andopposite forces to bend the rolls, and in the second form the cylindersare mounted on the housings themselves, a cylinder being provided foreach roll end. In the latter construction, which has the advantage ofallowing quick work roll changing, since in this arrangement thecylinders are not mounted between the journals as is the case in theformer, the cylinders are mounted on the housings. In this arrangementthe reaction forces of the cylinder are taken by the housings whichmeans that the housings must be built to resist the additional forces,substantially adding to the expanse of the mill. Of equal importance,when the cylinders are mounted on the housing, which is also true whenthey are arranged between the journals, the screws of the mill aresubject to the total bending forces in addition to the rolling loads.

The present invention provides a crown control system for a rolling millor like device wherein the reaction forces from the bending cylindersare not imposed upon 3,3ti4,715 Patented Jan. 23, 1968 the housing andwherein the screws of the mill are not subject to any bending forces.

Accordingly, one of the objects of the present invention is to provide,say for example, in connection with a 4-high mill, an independent beampositioned between the screws and the chocks of the upper backup rolls.To this beam there is connected at each end a double piston cylinderassembly, each cylinder being mounted on the mill, one piston thereofbeing connected to the beam and the other to the end of the roll, thearrangement being such that equal and opposite forces are transmitted tothe beam, and as a result no forces are imposed on the housings or themill screws.

In one form, in connection with a 4-high-mil1, at the top of the mill abeam is arranged between the chocks of the upper backup roll and thescrews, and at the bottom of the mill at similar beam is provided whichis positioned between the chocks of the backup roll and the housings.

These objects, as well as others, will be more readily understood whenthe following specification is read in light of the accompanyingdrawings of which:

FIGURE 1 is an elevational view, partly in section, of a 4-high millillustrating one embodiment of the present invention; and

FIGURE 2 is an end elevational view of the mill shown in FIGURE 1,certain components of the mill being shown in section.

With reference to these drawings there is illustrated a 4-high millcomprising two vertically arranged, spacedapart housings 11 and 12, thehousings having customary windows 13 and 14 into which is received apair of work rolls 1S and 16, each work roll being backed up in turn bya backup roll 17 and 18, respectively.

As shown best in FIGURE 2, the journals of each roll are received inbearing chocks, the work roll chocks being identified by the number 19and the backup bearing chocks by the number 20. In the customary mannerthe work rolls are urged away from each other and against theirrespective backup rolls by balance piston cylinder assemblies 21 mountedin the lower work roll chocks 19.

With reference now to the upper portion of the mill, it will be notedthat between the housings and extending through the windows 13 and 14there is a horizontally arranged beam 23 which for brevity referencewill be made to only one side of the mill. The lower surface of the beamin the vicinity of the chock 20, is provided with a rocker plate 24which engages a similar rocker plate 25 formed on the top of theadjacent chock. Directly across from the area where the beam engages thechock and on its upper surface there is provided a raised portion whichreceives a breaker block 26, the top of the breaker block having aspherical surface which is engaged by a complementary surface formed atthe bottom of the screw 27. The screw 27 is received in a nut 28 formedin the housing 11, the screw being rotated by a worm and wheel notspecifically shown on the drawings.

Drawing attention now specifically to the beam 23, as shown in FIGURE 1,the center is connected to a rod 31, which extends in a verticaldirection. To the upper end of the rod 31 there is connected a piston 32of a piston cylinder assembly 33 mounted on a separator 34 that connectsthe housings 11 and 12 together at the top of the mill. The pistoncylinder assembly 33 is employed to urge the chocks against the beam andthe beam against the screws. To this end, the beam at its lower end isprovided with opposed downwardly extending hooks 35 which cooperate withprojections 35a formed at the top of the chocks 20, whereby in operationof the piston cylinder assembly 33 the hooks engage the chocks and bringthem into contact with the bottom of the beam.

Still referring to the top of the mill, it will be noted that at theouter portion of the housings there is provided at each side of the millcylinders 36 which, as shown at the left of FIGURE 1, receive twopistons, 37a and 37b, one extending from the top of the cylinder and theother extending from the bottom.

The lower piston 37b engages a rocker plate 38 carried by the beam 23,the rocker plate being provided with a spherical surface whichcooperates with a spherical surface formed at the end of the piston,thereby allowing for any relative movement between the two pieces. Theupper piston 370, as shown best in FIGURE 2, is connected to a crossmember 39, to the ends of which there are connected identically pivotallinks 40 which extend downward of the rolls on the outside of the window13.

With reference now to the upper backup roll 17, and in still referringto but one side of the mill, it will be noted that outward of its mainbearing chock 20, there is provided a second bearing chock 41, which, asshown in FIGURE 2, is provided with opposed projecting horizontal wings42. The lower ends of the links 4t are formed so as to engage the wings42 of the bearing chock 41 whereby the bending force exerted by thecylinder 36 through the piston 37a is imposed upon the end of the roll17 causing the center portion of the roll to bend in the direction ofthe work roll.

It will be appreciated that upon the operation of the cylinder 36, aforce is imposed upon the beam 23 by the piston 37b in a directiontoward the work roll and a force is imposed upon the roll by the piston37a which imposes a second force upon the beam in a direction oppositefrom the first force. Moreover, the lever arm effect of these two forcesimposed on the beam are equal. Hence, there is a closed force circuitdeveloped whereby not only are there not any reaction forces imposedupon the housings 11 and 12, but the screws 27 are free from any bendingforces.

A generally similar arrangement is provided for the lower backup roll18, in which connection there is a lower beam 45 which extends betweenthe housings 11 and 12 and through the windows 13 and 14 thereof, thisbeing best shown in FIGURE 1 which also shows that the beam carries thebearing chocks 20 of the lower backup roll 13. For completion of thedescription, it will be noted that the chock 20 is separated from thebeam by a series of filler plates 46 which are replaceable so as tocompensate for the various diameters of the rolls employed in the mill.This, of course, is quite customary in mill design. FIGURE 1 also showsas to one side of the mill the relationship between the beam 45 and thehousing 11, wherein the beam rests upon the housing, there being rockerplates 48 provided so as to allow for relative movement between thesetwo elements. Outward of the ends of the beam there are provided on thehousings 11 and 12 cylinders 49. The cylinder, in referring to one sideof the mill, as in the case of the cylinders 36, is provided with twooppositely arranged pistons 51:: and 51b, 51a being the upper pistonwhich engages the lower surface of the beam 45 through a sphericalbearing block 52 provided for allowing for relative movement between thebeam and the piston 51a. The piston 51b extends downwardly from thecylinder 49 and is connected to a cross member 53, to which arepivotally secured at its outer ends, elongated links 54 extending towardthe work roll in such a way as to be clear of the window 13.

Outward of the main bearing chock 20 of the lower backup roll 18 is asecond bearing chock 55, the chock of which, as shown in FIGURE 2, hashorizontal wings 56 engaged by the links 54 and through which means thebending force of the piston cylinder assembly 49 is applied to the lowerroll 18 in a way to bend the central portion of the roll 18 in adirection of the lower work rolls 16. This arrangement, as in thearrangement pro vided for the upper backup roll 17, provides a closedforce circuit wherein the piston 51a imposes a force on the beam in onedirection and the piston 51b imposes an equal, but opposite force on thebeam through the chock 20, whereby the bending forces are self containedand are not imposed upon the housings 11 and 12.

It will be appreciated that various components of the mill illustratedhave not been referred to since they are quite common and that someelements have not been shown, since again they are well known in theart. It will be further appreciated that while the present invention hasbeen illustrated in connection with a 4-high mill, it may be used inother types of mills as well as other types of processing equipment,such as rubber and paper calenders.

In accordance with the provisions of the patent statutes, I haveexplained the principle and operation of my invention and haveillustrated and described what I consider to represent the bestembodiment thereof. However, I desire to have it understood that Withinthe scope of the appended claims, the invention may be practicedotherwise than as specifically illustrated and described.

I claim:

1. In a rolling apparatus including a pair of cooperative materialreducing rolls adapted to deflect away from the material being rolledunder the rolling loads,

a housing having a window for receiving the rolls,

bearing-chock assemblies mounted on the ends of the rolls for rotatablysupporting the rolls in said housat least one of said rolls havingopposed end portions extending outward of said bearing-chock assemblies,

a cross member arranged parallel to said one roll between itsbearing-chock assemblies and said housing and having portions extendingoutward of the bearing-chock assemblies of said one roll,

force exerting means for each extending portion of said one roll havingdisplaceable elements connectable to the roll extending portions forimposing bending forces thereon to control the deflection of said oneroll,

said force exerting means arranged with respect to said cross memberthat the reaction of the force exerted to displace said elements istaken by said cross memher and not by said housing.

2. In a rolling apparatus according to claim 1 wherein said cross memberincludes portions adapted to receive the rolling loads from thebearing-chock assemblies of said one roll and transfer them to saidhousing.

3. In a rolling mill and like apparatus:

a pair of housings,

windows in said housings,

a pair of working rolls received in said windows,

a backup roll for each work roll received in said windows,

bearing-chock assemblies mounted on the ends of the backup rolls forrotatably supporting the ends of the rolls in said housings,

said backup rolls having portions extending outward of saidbearing-chock assemblies,

a cross member for each backup roll arranged parallel to the backuprolls and between their bearing-chock assemblies and said housing andhaving portions extending outward of their bearing-chock assemblies,

a force exerting means for each extending portion of the backup rollsand having displaceable elements connectable to the roll-extendingportions for imposing bending forces thereon,

said force exerting means arranged with respect to said cross membersthat the reaction of the forces exerted to displace said elements istaken by said cross members and not by said housings.

4. In a rolling mill according to claim 3, wherein the said relationshipbetween the backup rolls and said cross members at the effectiveapplication. points of the bending forces and reaction forces is suchthat the lever arms of the bending forces are equal to the lever arms ofthe reaction forces.

5. In a rolling mill or like apparatus according to claim 3, including aroll adjusting means carried by said housings for adjusting the verticalposition of the uppermost backup roll, the construction being such thatthe roll adjusting means is not subject to any roll bending forces, and

means for urging the member associated with the uppermost backup rolltowards the roll adjusting means.

6. In a rolling mill or like apparatus according to claim 3, whereinsaid force exerting means comprises piston cylinder assemblies eachhaving two pistons, one piston connected to the end of the backup rollsand the other piston engages with said member.

7. In a rolling mill or like apparatus according to claim 6, whereineach said piston cylinder assembly is located in the same vertical planecontaining the axes of the rolls and associated with said means forconnecting said force exerting means to said roll ends,

said connecting means including a cross member connected to the pistonsemployed to apply the bending forces to the backup rolls, and whereinsaid rolling mill further includes,

a pair of arms having their one end pivotally connected to the outerends of the cross member, the other ends of said arms having projectingportions, and

projecting portions on said bearing-chock assemblies engageable by saidprojections of said arms.

References Cited UNITED STATES PATENTS 2,897,538 8/ 1959 Shapiro et al.72-245 X 3,171,305 3/1965 Stone 72-241 3,212,314 10/1965 Sieger 72-2253,250,105 5/1966 Stone 72240 CHARLES W. LANHAM, Primary Examiner.

20 A. RUDERMAN, Assistant Examiner.

